This section provides background information related to the present disclosure which is not necessarily prior art.
When ophthalmic surgery is performed, an ophthalmic illumination system is used to illuminate the interior of a patient's eye so that the surgeon may view the surgical site. In a typical ophthalmic illumination system, light is collimated and focused onto the entrance pupil of an optical fiber that transmits light to an opto-illuminator, or light probe. A tip of the probe is inserted into an incision in the eye.
It is highly desirable to be able to control the brightness of illumination at the surgical site. In illumination systems in which filament lamps have been used, electrical power to the light source may be reduced to lower the brightness of the source and accordingly the illumination of the site. Reducing the power, however, can change the color temperature of the light and affect the quality of illumination. Furthermore, intensities of new, high-brightness light sources such as zenon arc lamps typically are not easily controlled through electrical means.